I know the Roaring Spring is the last water before the top. I can handle 5 miles.

I Don't know if the creek is generally accessible between Roaring Spring and Phantom. All I need is one spot about mid-way to refill. I've been surprised before by the elevation between the a trail and the thin blue line next to it.

when you leave Phantom Ranch for the North Rim you will travel right at creek level for 3-4 miles. Beyond that I don't remember any sources where you can easily use your water filter.

The pump house is right on the trail about 5 miles below the north rim. I doubt the water is on all winter, but probably longer than at Cottonwood.the Roaring Springs themselves are quite a bit off route.I think there is a creek just before the pump house, there was a bridge, but I don't recall exactly how close you are to the water.

above the Pump House there are no sources where you can use your water filter.